The present invention relates to radiological imaging, and in particular to methods of MRI imaging of soft tissue.
The limitations of conventional X-ray imaging in detecting and diagnosing soft tissue injuries, that is structures other than calcified bone, is well known. Soft tissue, being much less dense than bone, has either too low a contrast to be observed, or is obscured by the bone structures, as the x-ray itself is a projected image in which x-rays are attenuated as they pass through the patient.
Magnetic resonance imaging (MRI) provides images of tissues not generally visible in x-rays, as well as bone. Rather than the images being a projection through the tissue and organ from the front to the back of the image plane, as in conventional x-rays images, like Computed tomography (CT), MRI can be obtained of thin slices at different positions and orientations in any plane. Further, MR has much greater soft tissue contrast than CT making it especially useful in neurological, musculoskeletal, cardiovascular and oncological diseases. Unlike CT it uses no ionizing radiation. The scanner creates a powerful magnetic field which aligns the magnetization of hydrogen atoms in the body. Radio waves are used to alter the alignment of this magnetization. This causes the hydrogen atoms to emit a weak radio signal which is amplified by the scanner. This signal can be manipulated by additional magnetic fields to build up enough information to reconstruct an image of the body.
Magnetic Resonance Imaging while capable of imaging soft tissue, as currently practiced has numerous limitations in identifying soft tissue injuries. While improvements in MRI scanning techniques have reduced the acquisition time, imaging is still a serial technique where a slice of the patient is imaged by precise positioning of a magnetic field and the imposition of gradients onto the slice. Thus, MRI has the advantage over X-ray in that surrounding structure is eliminated, while X-ray are a projection, with denser tissue obscuring features in finer tissue. However, as one attempts to acquire a sequence of MRI images dynamically, with limited motion between them, the resolution is inherently reduced as the speed of acquisition is increased to acquire additional frames.
Unfortunately, a failure to find soft tissue injuries by MRI frequently leads to incorrect diagnosis, or the assumption that the patient is exaggerating about the symptoms of pain and discomfort, or are of a psychological rather than physical origin.
It is now appreciated, in light of the present invention, that because MRI is so specific and sensitive soft tissue injuries are more frequently missed than identified. The ability to know early on in a patient's injury on what exactly has been traumatized is likely to result in better clinical outcomes for patients, and less risk of further degeneration, progressive deterioration of a patient's condition from neglect or inappropriate treatments.
It is therefore a first object of the present invention to provide for the identification of soft tissue injuries that have been elusive to static conventional diagnostic imaging protocols.
It is a further object of the invention to avoid the waste of time and expense on unreasonable treatments and diagnostic studies that are made when soft tissue injury is overlooked or not fully understood.
It is a further object of the invention to provide for the assessment and evaluation of the soft tissue injuries in moving joints, and in particular injuries to the cervical spine. The proper assessment and evaluation directs the treating Physician into the best treatment/care plan necessary to help the injured patient, to minimize future pain and prevent treatments that can increase pain or cause further injury.